Recording source information in a build

[Jesse Glick]

Kelly O'Hair wrote:
> hg tip --template 'changeset={node}\n'

I would recommend using 'hg id', not 'hg tip':

1. If the developer has updated to a specific revision and built it, 'hg 
id' would be accurate, but 'hg tip' would be meaningless.

2. If there are local modifications, 'hg id' will record that fact (with 
a '+'), which is good to know.

It will also include tag information, which may or may not be desirable.

I would expect 'java -version' to include the changeset ID, if it were 
built from sources and was not a formal release.

> TREES:=$(shell hg ftrees)

Or could just search for direct subdirs with .hg subsubdirs. A lot 
faster, does not use the forest extension, and should work for the 
OpenJDK forest at least.